Lucky you. I was doing catalogs of about 3000 images. Spent a great deal of time working with my technical staff trying to pinpoint any causes outside of Lr. Could not find any. And Lr is theonlyprogrami have crash and never had a crash on lr2 or lr3

Main catalog on desktop is just under 70000 images . Use notebook in field and was Exporting daily shoot of about 3000 images per day and then importing into main catalog on desktop. 7d ,5 d mkii and 5d mk iii raw

At this point I created a Windows system image. I then remembered that Lightroom, and not just camera raw, had to be updated to support the 5D mark 3. After lightroom 4.1 RC2 install, I started getting full system crashes, typically when I had lightroom open. 3 days of trying to figure out what was going on and I gave up. Yesterday I reimaged my system to pre-lightroom4.1rc2 and so far, no crashes (of course I cannot work on my 5d mark 3 images in lightroom currently).

good news, bad news.....first the bad news, sorry others are having it....good news, is that this many having it might help provide the clues to fixing it. I have a good copy of LR4.1 rc2 on my notebook , a big photo opp the next several days and plenty of import export time next week....hopefully we can collectiviely identify what is causing the problem and go forward.

I had the same problem with RC1 so I downloaded RC2 in the hope that it would stop the crashing. In my case the programme would not allow me to move from Library to Develop mode without crashing. It turned out that RC2 did not help. However I finally worked out that the most recent change I had made to the computer (Dell machine running Windows 7) was to install an updated driver for a Wacom tablet. For some reason this driver was interacting with Lightroom 4 and causing it to crash. Once the tablet driver was removed Lightroom is behaving itself again.

hate your are having that experience but I guess misery loves company. Unfortunately, I need to RC for processing the 5dmkiii images or go back to using the DNG converter...in any case, even if the crashes were eliminated, the processing speed is best timed with a calendar....killing my productivity....and I use the Nik filters so I prefer to come out of LR as a smart object in Photoshop.....agonzingly slow....hope they figure this out because I am way behind on processing shoots in Alaska and Minnesota....

Mine isn't crashing as frequently as yours, it's more that it encounters a problem when looking at the previews then says it will try to rectify the problem when reopened. but it doesn't, I have to reboot the computer.

How do we register this problem, have we done it by using this thread?

not sure how to register....I scanned a number of the popular nature photography forums and see noted pros complaining about the slowness and their frustration....I have not posted on those forums about the problems i am seeing but may do so in hopes they have a bigger voice....With the new 5dmkIII in hand and taken on a number of 5 day wildlife shoots already , the 1dx on order and a 21 day safari coming up, it is very frustrating when I think of where the necessary version of Lightroom is at the moment...I admire and am a big advocate of lightroom going back to LR2, but this is killing me.....hope they discover/fix the issue soon

I too am having serious issues with LR4 crashing. Again, LR3 never has. I simply did an install of LR4, nothing has changed on the system, no other installs, now it fails every 3-4 image edits! Really frustrating! Come on Adobe, please get this sorted and a patch released asap.Jacs

mine did same – I have epson printer and HP printer both usb – I unplug them when working in LR- and unplug sd cards etc. I don’t get any crashes when I don’t use usb’s. hope your solution is that simple.

I was getting some crashes with LR 4.1RC2, sometimes taking out Win7x64 as well. I seem to have solved that by uninstalling several things. The most likely culprits were the AMD graphics card stuff. So I uninstalled the Catalyst center, Hydravision, the 3D stuff, - everything except the basic graphics driver. I also uninstalled Windows NEF codec, and Nikon's Nef codec, and the standalone Noise Ninja, so it wasn't a very good experiment. But it cured the crashes. I didn't bother trying to find out exactly which was responsible. Graphics drivers are notoriously buggy, and the nVidia control center was noted for causing problems back in LR2 days, so I would put my money on them being responsible.

I am having LR 4.1 RC2 take out win7x64 as well. I don't have the Amd graphics stuff or standalone noise ninja...I do have the nVidia control center....Never had any problems until LR4...Very frustrating

I am also crashing on Win7 64bit...but not just Lightroom, it actually crashes my whole machine. I'm on a fresh install of Win7 with only CS6 & Lightroom installed. Lightroom so far has been the only program to cause this, and it typically happens when I'm adjusting filters or moving sliders for example. I'm guessing it's when I'm taxing the CPU/memory a bit...However, when performing the same type of tasks in Photoshop, AE, etc., I have not experienced any crashes. I've ran some diagnostics on my memory as well as my hard drives to hopefully rule out any hardware issues, and it all seems to check out OK. Because it's crashing the whole machine, I'm unfortunately getting no feedback in the system/error logs. I'm at a loss right now, and it seems others are only having application crashes.

Wizard155, this is interesting...I also had Quicktime installed (regular, not pro) and after reading your post I went ahead and uninstalled it. It's still a bit earliy to be 100% sure, but since doing so I have not been able to reproduce a crash yet (which before was happening at some point everytime I ran LR). For a test I was wildly moving sliders, jumping between images quickly, applying filters etc. to get RAM and CPU up and was still not able to reproduce a crash. This is promising, and I will update again if my results start to vary. Thanks!